Method for making renewable fuels

ABSTRACT

Multiple catalytic processing stations enable a method for producing volatile gas streams from biomass decomposition at discrete increasing temperatures. These catalytic processing stations can be programmed to maximize conversion of biomass to useful renewable fuel components based on input feedstock and desired outputs.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/071,016 (now U.S. Pat. No. 8,143,464), filed Mar. 24, 2011, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates generally to methods for making renewablefuels, and more particularly to the thermal chemical conversion ofbiomass to renewable fuels and other useful chemical compounds,including gasoline and diesel, via a series of catalysts using aprogrammable system.

DESCRIPTION OF THE RELATED ART

As the world continues to run through its precious resources of fossilfuels, it is going to be forced to turn to other sources of energy.Present global objectives include getting energy cheaply and quickly.Through the ages, mankind has turned to biomass to furnish energy interms of heat by burning wood and other biomass. This is inherently avery inefficient process. Combustion may be made more efficient byintroducing programmability. It is similar to introducing computers to abuilding that needs to be heated. In order to heat the building onlywhen the person is present, one places a sensor in the building so thatthe heater turns on when the sensor detects a person. This is an exampleof a programmable system. Similarly, a programmable system may beintroduced for chemical bond breakage resulting in efficient conversionof biomass to higher value added products, wherein only the minimumnumber of bonds are broken and, consequently, the minimum amount ofenergy is spent breaking these bonds.

Bond breaking and making are essential aspects of conversion of biomassto industrially useful products such as gasoline and diesel. Variousforms of laboratory and small scale commercial biomass pyrolyzers havebeen developed to generate useful chemical products from the controlledpyrolysis of biomaterials ranging from wood chips to sewage sludge.Although some pyrolyzers are focused simply on producing syngas, thereis considerable effort in the development of milder pyrolyzingconditions, which typically results in a condensed liquid commonlycalled bio-oil or pyrolysis oil. Many forms of pyrolyzers have beendeveloped at the laboratory level to produce these intermediatecompounds, which are collectively referred to as bio-oil or pyrolysisoil. Configurations include simple tube furnaces where the biomass isroasted in ceramic boats, ablative pyrolyzers where wood is rubbedagainst a hot surface, various forms of fluidized bed pyrolyzers wherebiomass is mixed with hot sand, and various simpler configurations thatare based on earlier coking oven designs.

The fundamental problem with the resultant pyrolysis oil is that it ismade up of hundreds to thousands of compounds, which are the result ofsubjecting the raw biomass to a wide range of temperature, time, andpressure profiles in bulk. When this process is complicated by thethousands of major bio-compounds in the original bio-feedstock, theresult is a nearly intractable array of resultant compounds all mixedtogether. Pyrolysis oils from such processes are typically notthermodynamically stable. They contain active oxygenated free radicalsthat are catalyzed by organic acids and bases such that these oilstypically evolve over period of a few days from light colored liquids todark mixtures with tar and resinous substances entrained in the mix.Also, attempts to re-gasify pyrolysis oil typically result in additionalchemical reactions, which produce additional biochar and a shift tolower molecular weight components in the resulting gas stream. Althoughfairly high yields of pyrolysis oil can be achieved in laboratory scaleexperiments, larger industrial scale demonstration projects typicallyproduce much lower yield. This is presumably due to the wider range oftemperatures, hold times, and localized pressures within the much largerheated three dimensional volumes of such scale-up architectures.

Previous efforts to introduce a programmable adaptability to catalyticsystems include Gehrer's design of building several parallel reactors,in analogy to a microprocessor bus, to study catalytic gas reactions.(Journal of Physics E: Scientific Instruments 18 (1985) 836). U.S. Pat.No. 6,548,026 by Dales et al. and U.S. Pat. No. 6,994,827 by Safir et.al. disclose programmable parallel reactors capable of controllingvessel stirring rate, temperature and pressure. Additionally, U.S.Patent Application 2010/0223839 to Garcia-Perez et al. discloses heatingbiomass to a first temperature aimed to enhance the subsequent anhydrosugar content developed in the oil portion of the biomass pyrolysisproduct. The aim is to enhance the fermentation capability of the oilportion for subsequent ethanol production. This is an example of asomewhat programmable system for biomass conversion.

BRIEF SUMMARY OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention provide a system and method for theconversion of biomass to renewable fuels. By renewable fuel is meant anycombustible fuel that is derived from biomass and that is useful fortransportation or other purposes, including such fuels as gasoline,diesel, jet fuel, or other useful fuel blends (such as a blend ofbenzene, toluene and xylene (BTX))). In one embodiment, the systemcomprises a device containing a programmable number of processingstations (N) and an array of catalysts; a means for subjecting biomasswithin these stations to programmable temperatures (Tstart); a means forincrementing individual processing station temperatures by programmableincrements (ΔT) to produce a volatile and non-volatile component; ameans for incrementing the non-volatile component temperature by ΔT tofurther produce additional volatile and non-volatile components; and ameans for subjecting the volatile components generated in each stationthrough a series of catalysts selected from the group of dehydrationcatalysts, aromatization catalysts, and gas-upgrading catalysts toproduce at least one renewable fuel.

Some embodiments of the invention involve a system and method forcreating a programmable process wherein chemical compounds from biomassdecomposition are routed to distinct catalyst chains to produce productscontaining renewable fuels and other value added products.

Further embodiments of this invention are directed toward an efficientsystem for the conversion of biomass pyrolysis products.

Additional embodiments are directed toward a process for extracting themaximum amount of energy from biomass for the conversion to gasoline ordiesel that depends on the temperature of devolatilization of thebiomass.

Yet another embodiment of this invention involves a process forextracting the maximum amount of energy from biomass for the conversionto gasoline or diesel that depends on load balancing a catalyst outputat certain temperatures.

Other features and aspects of the invention will become apparent fromthe following detailed description, taken in conjunction with theaccompanying drawings, which illustrate, by way of example, the featuresin accordance with embodiments of the invention. The summary is notintended to limit the scope of the invention, which is defined solely bythe claims attached hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention, in accordance with one or more variousembodiments, is described in detail with reference to the followingfigures. The drawings are provided for purposes of illustration only andmerely depict typical or example embodiments of the invention. Thesedrawings are provided to facilitate the reader's understanding of theinvention and shall not be considered limiting of the breadth, scope, orapplicability of the invention. It should be noted that for clarity andease of illustration these drawings are not necessarily made to scale.

FIG. 1 is a drawing illustrating N processing stations on a race track,wherein each processing station is operating at a particulartemperature.

FIG. 2 is a flow diagram illustrating a programmable catalyst chain withthree stations, in accordance with the principles of the invention.

FIG. 3 is a more detailed flow diagram of the programmable catalystchain of FIG. 2, in accordance with the principles of the invention.

FIG. 4 is a flowchart depicting an algorithm that depends onincrementing the processing station temperature until a desired maximumtemperature is reached, in accordance with the principles of theinvention.

FIG. 5 is a flowchart depicting an algorithm that depends on balancingoutput from various catalyst chains, in accordance with the principlesof the invention.

FIG. 6A is a plot of fuel output versus temperature for sunflower seedsusing a dehydration catalyst, aromatization catalyst and gas-upgradingcatalyst; FIG. 6B shows a comparative output of the A cut (afterdehydration catalyst) versus U.S. Diesel #2 and Biodiesel B99; and FIGS.6C and 6D show gas chromatograms (GC) data for renewable fuels obtainedafter the aromatization catalyst and gas-upgrading catalyst.

FIG. 7 is a GC plot of volatile gases collected after the aromatizationcatalyst using red fir as input biomass.

The figures are not intended to be exhaustive or to limit the inventionto the precise form disclosed. It should be understood that theinvention can be practiced with modification and alteration, and thatthe invention be limited only by the claims and the equivalents thereof.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

The present invention is directed toward a programmable system forrouting biomass decomposition products through a system comprised ofprocessing stations and a series of catalysts. It realizes aprogrammable system for maximizing output from a pyrolysis system. Thereare three basic approaches in this programmable system: a) routing basedon knowledge of the initial composition of the biomass, b) routing basedon knowledge of the temperature of biomass devolatilization, and c)routing based on load balancing. The full nature of these approacheswill now be described by reference to the figures.

Methods of introducing biomass into a processing station includeintroduction via conveyor belts, hoppers, and/or pulverizers. Thepyrolyzer described herein may include these components enveloped in onesystem, where, for example, the pulverization and pyrolysis componentsare intimately connected. Biomass may be introduced in raw form or dryform, or may be dried within the pyrolysis chamber when the pyrolysisstarts.

As used herein, the term ‘biomass’ includes any material derived orreadily obtained from plant sources. Such material can include withoutlimitation: (i) plant products such as bark, leaves, tree branches, treestumps, hardwood chips, softwood chips, grape pumice, sugarcane bagasse,switchgrass; and (ii) pellet material such as grass, wood and haypellets, crop products such as corn, wheat and kenaf. This term may alsoinclude seeds such as vegetable seeds, fruit seeds, and legume seeds.

The term ‘biomass’ can also include: (i) waste products including animalmanure such as poultry derived waste; (ii) commercial or recycledmaterial including plastic, paper, paper pulp, cardboard, sawdust,timber residue, wood shavings and cloth; (iii) municipal waste includingsewage waste; (iv) agricultural waste such as coconut shells, pecanshells, almond shells, coffee grounds; and (v) agricultural feedproducts such as rice straw, wheat straw, rice hulls, corn stover, cornstraw, and corn cobs.

Referring to FIG. 1, a series of N processing stations 50 are arrangedaround a rectangular track 52 sequentially. A processing station 50 maycomprise any of a number of well-known pyrolysis reactors, includingfixed bed reactors, fluidized bed reactors, circulating bed reactors,bubbling fluid bed reactors, vacuum moving bed reactors, entrained flowreactors, cyclonic or vortex reactors, rotating cone reactors, augerreactors, ablative reactors, microwave or plasma assisted pyrolysisreactors, and vacuum moving bed reactors. It ay also comprise a chamberin a biomass fractionating system as described in co-owned U.S. PatentPublication No. 2010/0180805, the content of which is incorporatedherein by reference in its entirety.

At any one time, each processing station 50 is operated at a certaintemperature (marked next to each processing station in FIG. 1 as T₁ . .. T_(N)). Thus, the Nth station is operated at temperature T_(N). Thefirst processing station is Station 1. Each processing station 50 can bedialed to any temperature that is equal to or higher than the previousprocessing station. The starting processing station temperature istypically determined by the initial composition of the biomass. Thedevice accommodates a total of N processing stations, where N isoperator adjustable from 2 to 1000, preferably between 2 and 100, andmost preferably between 2 and 50. A station temperature can beincremented by a variable increment ΔT, which can be in the range of 0°C. to 200° C. In one embodiment, all processing stations 50 operate atthe same temperature. In another embodiment, each subsequent processingstation temperature is incrementally higher by ΔT from the previousprocessing station. In still another embodiment, a group of adjacentprocessing stations are operated at the same temperature T, followed byanother group of adjacent processing stations which are operated attemperature T+x*ΔT, followed still by another group of processingstations operating at temperature T+y*ΔT, where x and y are any numbersgreater or equal to 1.

The processing stations 50 produce volatile and non-volatile componentswhen heated. Because the material can be heated within a relativelynarrow temperature range, the non-volatile component (in the form ofpartially formed char) has additional volatile components embeddedtherein, which are extractable and processed in subsequent processingstations. The output of these processing stations is connected to anarray of catalysts as described below.

Biomass is typically comprised of a wide array of compounds classifiedwithin the categories of cellulose, hemicelluloses, lignin, starches,and lipids. These compounds go through multiple steps of decompositionwhen subject to the pyrolysis process. For example, hemicellulosescomprise C5 sugars such as fructose and xylose, which yield furfural andhydroxymethylfurfurals upon thermolysis. The latter compounds can befurther converted to fuel intermediates furan and tetrahydrofuran. Therelatively narrow temperature windows experienced within a processingstation 50 allows for the collection of these useful intermediates.

FIG. 2 depicts an embodiment of the present invention having eightprocessing stations 50 and a series of catalyst channels comprising adehydration catalyst 60, an aromatization catalyst 61 and agas-upgrading catalyst 62. The output from each catalytic array whencooled is comprised of volatile gases, renewable fuel and water. Thevolatile gases are then programmed to pass through subsequent catalyticcolumns. Depending on the temperature of the processing station 50 andthe biomass composition, the volatile components from any givenprocessing station can be channeled through one or more catalysts 60,61, 62 using selector switches 55, 56, 57. Line 21 shows that anoptional co-solvent may be added as an additional input to thearomatization catalyst 61. The co-solvent may be generated from atypical syngas converter 64. Carbon monoxide and hydrogen for the syngasconverter (to generate the co-solvent) may be obtained via well-knownreactions with the left-over carbonaceous solid in a processing station50. The co-solvent may comprise oxygenates such as aldehydes, alcohols,ketones, ethers, and carboxylates, as well as hydrocarbons.

If the volatile components from the processing station 50 are selectedto go through a dehydration catalyst 60, then the output is passedthrough a room temperature separator 32, which separates the output intowater, renewable fuel 33, and volatile gases 34. The volatile gases arethen routed through the aromatization catalyst 61 to produce a productthat upon cooling with cold separator 35 gives water, renewable fuel 36and volatile gases 37, which may include combustible gases 41. Thesecombustible gases can then be released via a variable release valve 58.The variable release valve can control the routing of the volatile gases37 to either a gas-upgrading catalyst chamber, or a combustible gastreatment plant, or both. Upon cooling via cold separator 38, theproduct from the gas-upgrading catalyst 62 produces water, renewablefuel 39 and volatile gases 40, which may include combustible gas mixture42. This combustible gas mixture can be either treated in a combustiblegas treatment plant or recycled via a recirculation pump 59 to thearomatization catalyst chamber. In another embodiment, the combustiblegas mixture 42 may be recycled to one or more of the following: (a) atleast one or more of the processing stations 50, (b) the dehydrationcatalyst 60, (c) the aromatization catalyst 61, and the (d)gas-upgrading catalyst 62.

FIG. 3 shows an embodiment 300 of the present invention using knowledgeof the initial composition of the biomass for converting various typesof biomass feedstocks with three processing stations 50 and an array ofcatalytic columns for optimal product yield. The biomass feedstocks invarious stations can come from a single biomass input which aresubsequently processed using the three stations, or from multipleindependent biomass inputs. While the number of processing stations canvary, the same catalytic columns are used to convert the volatile gasesto renewable fuels. The order in which the catalytic columns areselected can vary.

Station 1 when fed with a lipid rich biomass (A) produces a productcomprising a volatile gas and a carbonaceous solid. Station 1 preferablyoperates at less than 300° C. The volatile components are passed througha dehydration catalyst 60 to produce a first product. This first productis cooled using a room temperature trap and is comprised of water, afirst renewable fuel and a second volatile component. The firstrenewable fuel is then recovered. The dehydration catalyst operates atless than 2 bar pressure, preferably in the temperature range of400-700° C., most preferably in the range of 400° C. to 500° C.

The dehydration catalyst 60 can be any acid catalyst. Suitable acidcatalysts for the present invention are heterogeneous (or solid) acidcatalysts. The at least one solid acid catalyst may be supported on atleast one catalyst support (herein referred to as a supported acidcatalyst). Solid acid catalysts include, but are not limited to, (1)heterogeneous heteropolyacids (HPAs) and their salts, (2) natural clayminerals, such as those containing alumina or silica (includingzeolites), (3) cation exchange resins, (4) metal oxides, (5) mixed metaloxides, (6) inorganic acids or metal salts derived from these acids suchas metal sulfides, metal sulfates, metal sulfonates, metal nitrates,metal phosphates, metal phosphonates, metal molybdates, metaltungstates, metal borates, and (7) combinations of groups 1 to 6.

Suitable HPAs include compounds of the general Formula X_(a)M_(b)O_(c)^(q−), where X is a heteroatom such as phosphorus, silicon, boron,aluminum, germanium, titanium, zirconium, cerium, cobalt or chromium, Mis at least one transition metal such as tungsten, molybdenum, niobium,vanadium, or tantalum, and q, a, b, and c are individually selectedwhole numbers or fractions thereof. Methods for preparing HPAs are wellknown in the art. Natural clay minerals are well known in the art andinclude, without limitation, kaolinite, bentonite, attapulgite,montmorillonite and zeolites. Suitable cation exchange resins arestyrene-divinylbenzene copolymer-based strong cation exchange resinssuch as Amberlyst® (Rohm & Haas; Philadelphia, Pa.), Dowex® (forexample, Dowex® Monosphere M-31) (Dow; Midland, Mich.), CG resins fromResintech, Inc. (West Berlin, N.J.), and Lewatit resins such asMonoPlus™ S 100 H from Sybron Chemicals Inc. (Birmingham, N.J.). Whenpresent, the metal components of groups 4 to 6 may be selected fromelements from Groups I, IIa, IIIa, VIIa, VIIIa, Ib and IIb of thePeriodic Table of the Elements, as well as aluminum, chromium, tin,titanium and zirconium. Fluorinated sulfonic acid polymers can also beused as solid acid catalysts for the process of the present invention.

The second volatile component is then routed to an aromatizationcatalyst 61 to produce a second product. This second product in turn iscooled using a cold trap at 0-20° C., more preferably at 0-5° C. Theoutput from the cold trap is comprised of water, a second renewable fueland a third volatile component. The second renewable fuel is thenrecovered. The aromatization catalyst 61 is operated at less than 2 barpressure, preferably in the temperature range of 300° C. to 500° C.,most preferably in the range of 325° C. to 400° C. aromatizationcatalyst 61 can be comprised of MFI type zeolites and metal modified MFItype zeolites, where the metal is selected from the group consisting of:Group VIB metals, Group VIIB metals, Group VIII metals, Group IB metals,Group IIB metals, Ga, In, and all combinations thereof.

The third volatile component is then routed to a gas-upgrading catalyst62 to produce a third product. This third product in turn is cooledusing a cold trap at 0-20° C., more preferably at 0-5° C. The outputfrom the cold trap is comprised of water, a third renewable fuel and afourth volatile component. The third renewable fuel is then recovered.The gas-upgrading catalyst 62 is operated at less than 2 bar pressureand preferably in the temperature range of 400° C. to 700° C., mostpreferably in the range of 500° C. to 600° C. The gas-upgrading catalyst62 can be comprised of metal modified MFI type zeolites, where the metalis selected from the group consisting of: Ga, Zn, In, Mo, W, Cr, Pt, Pd,Rh, Ru, Au, Ir, and combinations thereof. The fourth volatile componentcan be recirculated to at least one of the following: a) one or moreprocessing stations 50, b) the dehydration catalyst 60, c) thearomatization catalyst 61, d) the gas-upgrading catalyst 62, and e) acombustible gas treatment plant.

Referring still to FIG. 3, Station 2 can comprise a hemicellulose richbiomass (B) derived from another biomass feedstock or a carbonaceoussolid from a previous station 50 that contains volatile components thatdid not volatilize in the prior station. Station 2 preferably operatesat greater than 300° C. and less than 500° C. The temperature in Station2 can be programmably incremented (ΔT) by the operator. The temperatureincrement can preferably be in the range of 10-200° C. Station 2produces a product which is comprised of a volatile component and acarbonaceous solid that is different than the carbonaceous solidproduced in the previous station. The volatile component produced inStation 2 is then routed through the aromatization catalyst 61 toproduce a fourth product. This fourth product is then cooled using acold trap at 0-20° C., most preferably at 0-5° C. The fourth renewablefuel is then recovered. The output from the cold trap is comprised ofwater, a fourth renewable fuel and a fifth volatile component. Thearomatization catalyst 61 is operated at less than 2 bar pressure andpreferably in the temperature range of 300° C. to 500° C., mostpreferably in the range of 325° C. to 400° C.

The fifth volatile component is then routed to the gas-upgradingcatalyst 62 to produce a fifth product. This fifth product in turn iscooled using a cold trap at 0-20° C., most preferably at 0-5° C. Theoutput from the cold trap is comprised of water, a fifth renewable fueland a sixth volatile component. The fifth renewable fuel is thenrecovered. The gas-upgrading catalyst 62 is operated at less than 2 barpressure and preferably in the temperature range of 400° C. to 700° C.,most preferably in the range of 500° C. to 600° C. The sixth volatilecomponent can be recirculated to at least one of the following: a) oneor more processing stations 50, b) the dehydration catalyst 60, c) thearomatization catalyst 61, d) the gas-upgrading catalyst 62, and e) acombustible gas treatment plant.

Still referring to FIG. 3, Station 3 operates at greater than 500° C.processing either an independent lignin-rich biomass feedstock or theleftover carbonaceous solid from the previous station. Station 3produces a product which contains volatile gases and a differentcarbonaceous solid. These volatile components are passed through adehydration catalyst 60 to produce a sixth product. This sixth productis cooled using a room temperature trap and is comprised of water, asixth renewable fuel and a seventh volatile component. The sixthrenewable fuel is then recovered. The dehydration catalyst 60 operatesat less than 2 bar pressure and preferably in the temperature range of400-700° C., most preferably in the range of 400° C. to 500° C. Thedehydration catalyst 60 can be the same as described above.

The seventh volatile component is then routed to the previouslydescribed aromatization catalyst 61 to produce a seventh product. Thisseventh product in turn is cooled using a cold trap at 0-20° C., mostpreferably at 0-5° C. The output from the cold trap is comprised ofwater, a seventh renewable fuel and an eighth volatile component. Theseventh renewable fuel is then recovered. The aromatization catalyst 61is operated at less than 2 bar pressure and preferably in thetemperature range of 300° C. to 500° C., most preferably in the range of325° C. to 400° C.

The eighth volatile component is then routed to the previously describedgas-upgrading catalyst 62 to produce an eighth product. This eighthproduct in turn is cooled using a cold trap at 0-20° C., most preferablyat 0-5° C. The output from the cold trap is comprised of water, aneighth renewable fuel and a ninth volatile component. The eighthrenewable fuel is then recovered. The gas-upgrading catalyst 62 isoperated at less than 2 bar pressure and preferably in the temperaturerange of 400° C. to 700° C., most preferably in the range of 500° C. to600° C. The ninth volatile component can be recirculated to at least oneof the following: a) one or more processing stations 50, b) thedehydration catalyst 60, c) the aromatization catalyst 61, d) thegas-upgrading catalyst 62, and e) a combustible gas treatment plant.

The embodiment of FIG. 3 involves an approach that exploits knowing theinitial composition of the biomass input, and then adjusting the routingof the decomposition products based on this initial composition.Accordingly, given a hemicellulose rich feedstock, it may be beneficialto set all of the processing stations 50 to a temperature greater than300° C. Similarly, given a lignin-rich feedstock, it may be beneficialto operate all the processing stations 50 at temperatures greater than500° C. Such an operation is expected to utilize all the stations in themost efficient manner for maximizing fuel output.

Another approach entails the use of an algorithm that raises anindividual processing station temperature by ΔT until a desired endtemperature is reached. This approach is illustrated in FIG. 4, whichshows a temperature algorithm flowchart 400 for a single processingstation. For three cuts derived from lipids, hemicellulose and lignins,one would select T_(LOW) around 300° C., and T_(HIGH) around 500° C.

Referring to FIG. 4, T=T_(start) at operation 405. Operation 410involves raising the biomass temperature by ΔT. Next, operation 415involves determining whether T<T_(LOW) for the lipids If so, the nextsteps entail routing the biomass through the lipid catalyst chain(operation 420), collecting the product (operation 425), and proceedingto raise the biomass temperature by ΔT (operation 410). If operation 415is false, operation 440 involves determining whether T_(LOW)<T<T_(HIGH)for the hemicellulose. If so, the next steps include routing the biomassthrough the hemicellulose catalyst chain (operation 445), collecting theproduct (operation 450), and proceeding to raise the biomass temperatureby ΔT (operation 410). If operation 440 is false, operation 470 involvesdetermining whether T>T_(HIGH) for the lignins. If so, the next stepsentail routing the biomass through the lignin catalyst chain (operation475), collecting the product (operation 480), and proceeding to raisethe biomass temperature by ΔT (operation 410). The algorithm ends ifoperation 470 is false.

Yet another approach involves load balancing the output from eachcatalytic chain in order to maximize product yield. This approach isillustrated in FIG. 5, which depicts a load balancing algorithmflowchart 500 for one processing station. According to this approach,knowledge of composition is not required. Rather, the optimal catalyticroute is determined by comparing product output yield from each route.Subsequently, the temperature is incremented until a final desiredtemperature is achieved.

Referring to FIG. 5, T=T_(start) at operation 505. Operation 510involves opening all routes. Next, operation 515 comprises raising thebiomass temperature by ΔT. At this point, this approach splits intothree routes, specifically catalyst chain A (operation 520), catalystchain B (operation 525), and catalyst chain C (operation 530). Productis collected for each catalyst chain in subsequent operations 540, 545,550. Operation 560 entails determining the optimal catalytic route iscalculated by comparing product output yield from each route anddetermining the catalyst chain having the highest product yield. Then,operation 565 comprises closing all routes except the one with thehighest yield. Operation 570 involves determining whether the productoutput is below a threshold level. If so, the algorithm proceeds to openall routes (operation 510). If not, the algorithm proceeds to raise thebiomass temperature by ΔT (operation 515).

Illustrative Example 1

Referring now to FIG. 6A, this illustrative example is the equivalent tosix processing stations 50 operating at six different temperatureswherein the input biomass is fed at 325° C. and the final carbonaceoussolid is removed at 575° C. 150 g of biomass consisting of commercialsunflower seeds along with dimethyl ether as co-solvent weredevolatilized starting at a temperature of 325° C. and ending at 575° C.with a temperature increment of 50° C. for every hour. 131 g of methanolwas passed through a silica alumina catalyst to generate the requiredco-solvent. The output was passed through three different catalystcolumns in series including a dehydration catalyst 60, an aromatizationcatalyst 61, and a gas-upgrading catalyst 62 as illustrated in FIG. 3for cut A. More particularly, this experiment employed a silica aluminadehydration catalyst, a Zn and Cr modified ZSM-5 aromatization catalyst,and a Ga modified ZSM-5 gas-upgrading catalyst. FIG. 6A is a chartshowing the fuel collected at each temperature for each catalyst athalf-hour intervals. A grand total of 46.5 ml of renewable fuel isproduced by the three catalysts by the end of the run, including: (i) atotal of 26.5 ml of renewable fuel collected from the aromatizationcatalyst 61, (ii) a total of 18 ml of renewable fuel collected from thedehydration catalyst 60, and (iii) a total of 2 ml of renewable fuelcollected from the gas-upgrading catalyst 62.

FIG. 6B is a chart showing the gas chromatogram profile of the renewablefuel collected from the dehydration catalyst 60 along with comparativecharts of regular US Diesel #2 fuel and Bio Diesel B99 obtained from acommercial source. The renewable fuel produced from the dehydrationcatalyst according to the present invention is significantly differentwhen compared to the Biodiesel B99 and more resembles the profile of theregular US Diesel #2. Gas chromatograms shown in FIGS. 6C and 6Drepresent renewable fuel composition from the aromatization catalyst 61and the gas-upgrading catalyst 62, respectively. Significant amount ofaromatic hydrocarbons are present in both renewable fuels.

Illustrative Example 2

This illustrative example is the equivalent to six processing stationsoperating at six different temperatures wherein the input biomass isagain fed at 325° C. and the final carbonaceous solid is removed at 525°C. 76 g of biomass consisting of commercial corn cobs along with 100 gof methanol were devolatilized starting at a temperature of 325° C. andending at 525° C. with a temperature increment of 50° C. for every hour.This example assumes that corn cobs contain significant amounts ofhemicellulose (C5 sugars), which may decompose in the presence of adehydration catalyst 60, leading to more breakage of chemical bonds thannecessary. Therefore, the output was passed through two differentcatalyst columns in series, one consisting of an aromatization catalyst61, followed by a gas-upgrading catalyst 62 as illustrated in FIG. 3 forcut B. In this example, ZSM-5 was employed as the aromatizationcatalyst, and Ga modified ZSM-5 was employed as the gas-upgradingcatalyst. A total of 29 ml of renewable fuel was collected by the end ofthe run from the aromatization catalyst, while a total of 5.5 ml ofrenewable fuel was collected from the gas-upgrading catalyst, Furtheranalysis of the two renewable fuels collected indicated significantpresence of aromatic compounds similar in composition as shown inIllustrative Example 1.

Illustrative Example 3

This illustrative example is the equivalent to six processing stationsoperating at six different temperatures wherein the input biomass isagain fed at 325° C. and the final carbonaceous solid is removed at 575°C. 100 g of biomass consisting of red fir wood along with 131 g ofmethanol were devolatilized starting at a temperature of 325° C. andending at 575° C. with a temperature increment of 50° C. for every hour.This example assumes that red fir contains significant amounts oflignins which are needed to be decomposed for efficient biomassconversion. The output was passed through two different catalyst columnsin series, beginning with the dehydration catalyst 60, and followed byan aromatization catalyst 61. This experiment utilized silica alumina asthe dehydration catalyst, and Zn and Cr modified ZSM-5 as thearomatization catalyst. A total of 30.5 ml of renewable fuel wascollected by the end of the run from the aromatization catalyst 61,whereas a total of 1 ml of renewable fuel was collected from thedehydration catalyst 60. While the fuel from the silica alumina catalystwas diesel-like, the fuel from the aromatization catalyst hadsignificant amounts of aromatic hydrocarbons. The volatile gases afterthe aromatization catalyst 61 had significant amounts of C1-C5non-condensable hydrocarbons, as shown in FIG. 7.

Although the invention is described above in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead can beapplied, alone or in various combinations, to one or more of the otherembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments.

Terms and phrases used in this document, and variations thereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as meaning “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; the terms “a” or“an” should be read as meaning “at least one,” “one or more” or thelike; and adjectives such as “conventional,” “traditional,” “normal,”“standard,” “known” and terms of similar meaning should not be construedas limiting the item described to a given time period or to an itemavailable as of a given time, but instead should be read to encompassconventional, traditional, normal, or standard technologies that may beavailable or known now or at any time in the future. Likewise, wherethis document refers to technologies that would be apparent or known toone of ordinary skill in the art, such technologies encompass thoseapparent or known to the skilled artisan now or at any time in thefuture.

The presence of broadening words and phrases such as “one or more,” “atleast,” “but not limited to” or other like phrases in some instancesshall not be read to mean that the narrower case is intended or requiredin instances where such broadening phrases may be absent. Additionally,the various embodiments not forth herein are described in terms ofexemplary block diagrams, flow charts and other illustrations. As willbecome apparent to one of ordinary skill in the art after reading thisdocument, the illustrated embodiments and their various alternatives canbe implemented without confinement to the illustrated examples. Theseillustrations and their accompanying description should not be construedas mandating a particular architecture or configuration.

The invention claimed is:
 1. A method for converting biomass torenewable fuels, comprising the steps of: (a) providing a devicecontaining a number of processing stations (N) and a series ofcatalysts; (b) subjecting biomass within a processing station to a firstprogrammable operating temperature (T) to produce a first volatile and afirst non-volatile component; (c) contacting the first volatilecomponent with an aromatization catalyst to produce a first productwhich on cooling to a temperature of 1-20° C. produces a second volatilecomponent, a first renewable fuel and water; (d) subjecting said firstnon-volatile component within a processing station different from (b) toa second programmable operating temperature (T+ΔT) to produce a thirdvolatile and a second non-volatile component; (e) contacting the thirdvolatile component with an aromatization catalyst to produce a secondproduct which on cooling to a temperature of 1-20° C. produces a fourthvolatile component, a second renewable fuel and water.
 2. The method ofclaim 1, wherein the processing station of step (b) is programmable suchthat the processing station temperature can be incremented by aprogrammable increment (ΔT), and wherein steps (b) and (d) are conductedin the same processing station.
 3. The method of claim 1, wherein steps(b) and (d) are conducted in different processing stations within thedevice of step (a).
 4. The method of claim 1, wherein the firstprogrammable operating temperature (T) is less than about 300° C.
 5. Themethod of claim 1, wherein the second programmable operating temperature(T+ΔT) is less than about 300° C.
 6. The method of claim 1, wherein theprogrammable operating temperature (T) is less than the secondprogrammable operating temperature (T+ΔT).
 7. The method of claim 1,further comprising recovering the first renewable fuel.
 8. The method ofclaim 1, further comprising contacting the second volatile componentwith a gas-upgrading catalyst to produce a third product which oncooling to a temperature of 1-20° C. produces a fourth volatilecomponent, a third renewable fuel and water.
 9. The method of claim 8,further comprising recovering the third renewable fuel.
 10. The methodof claim 8, further comprising subjecting the fourth volatile componentto at least one of the group consisting of: other processing stations, adehydration catalyst, an aromatization catalyst, a gas-upgradingcatalyst, and a combustion gas treatment plant.
 11. A method forconverting biomass to renewable fuels, comprising the steps of: (a)providing a device containing a number of processing stations (N) and aseries of catalysts; (b) subjecting hemicellulose-rich biomass within aprocessing station to a first programmable operating temperature (T) toproduce a first volatile and a first non-volatile component; (c)contacting the first volatile component with an aromatization catalystto produce a first product which on cooling to a temperature of 0-5° C.produces a second volatile component, a first renewable fuel and water;(d) subjecting said first non-volatile component within a processingstation different from (b) to a second programmable operatingtemperature (T+ΔT) to produce a third volatile and a second non-volatilecomponent; (e) contacting the third volatile component with anaromatization catalyst to produce a second product which on cooling to atemperature of 0-5° C. produces a fourth volatile component, a secondrenewable fuel and water.
 12. The method of claim 11, wherein theprocessing station of step (b) is programmable such that the processingstation temperature can be incremented by a programmable increment (ΔT),and wherein steps (b) and (d) are conducted in the same processingstation.
 13. The method of claim 11, wherein steps (b) and (d) areconducted in different processing stations within the device of step(a).
 14. The method of claim 11, wherein the first programmableoperating temperature (T) is between about 300-500° C.
 15. The method ofclaim 11, wherein the second programmable operating temperature (T+ΔT)is between about 300-500° C.
 16. The method of claim 11, wherein theprogrammable operating temperature (T) is less than the secondprogrammable operating temperature (T+ΔT).
 17. The method of claim 11,further comprising recovering the first renewable fuel.
 18. The methodof claim 11, further comprising contacting the second volatile componentwith a gas-upgrading catalyst to produce a third product which oncooling to a temperature of 0-5° C. produces a fourth volatilecomponent, a third renewable fuel and water.
 19. The method of claim 18,further comprising recovering the third renewable fuel.
 20. The methodof claim 18, further comprising routing the fourth volatile component toat least one of the group consisting of: other processing stations, adehydration catalyst, an aromatization catalyst, a gas-upgradingcatalyst, or a combustion gas treatment plant.
 21. A method forconverting biomass to renewable fuels, comprising the steps of: (a)providing a device containing a number of processing stations (N) and aseries of catalysts; (b) subjecting lignin-rich biomass within aprocessing station to a first programmable operating temperature (T) toproduce a first volatile and a first non-volatile component; (c)contacting the first volatile component with an aromatization catalystto produce a first product which on cooling to a temperature of 2-20° C.produces a second volatile component, a first renewable fuel and water;(d) subjecting said first non-volatile component within a processingstation different from (b) to a second programmable operatingtemperature (T+ΔT) to produce a third volatile and a second non-volatilecomponent; (e) contacting the third volatile component with anaromatization catalyst to produce a second product which on cooling to atemperature of 2-20° C. produces a fourth volatile component, a secondrenewable fuel and water.
 22. The method of claim 21, wherein theprocessing station of step (b) is programmable such that the processingstation temperature can be incremented by a programmable increment (ΔT),and wherein steps (b) and (d) are conducted in the same processingstation.
 23. The method of claim 21, wherein steps (b) and (d) areconducted in different processing stations within the device of step(a).
 24. The method of claim 21, wherein the first programmableoperating temperature (T) is greater than about 500° C.
 25. The methodof claim 21, wherein the second programmable operating temperature(T+ΔT) is greater than about 500° C.
 26. The method of claim 21, whereinthe programmable operating temperature (T) is less than the secondprogrammable operating temperature (T+ΔT).
 27. The method of claim 21,further comprising recovering the first renewable fuel.
 28. The methodof claim 21, further comprising contacting the second volatile componentwith a gas-upgrading catalyst to produce a third product which oncooling to a temperature of 0-5° C. produces a fourth volatilecomponent, a third renewable fuel and water.
 29. The method of claim 28,further comprising recovering the third renewable fuel.
 30. The methodof claim 28, further comprising contacting the fourth volatile componentwith a gas-upgrading catalyst to produce an fourth product which oncooling to a temperature of 0-5° C. produces a fifth volatile component,a fourth renewable fuel and water.
 31. The method of claim 30, furthercomprising recovering the fourth renewable fuel.
 32. The method of claim30, further comprising subjecting the fifth volatile component to atleast one of the group consisting of: other processing stations, adehydration catalyst, an aromatization catalyst, a gas-upgradingcatalyst, and a combustion gas treatment plant.